Year	Number
1980	111696
1981	106793
1982	105165
1983	120868
1984	128527
1985	176500
1986	197787
1987	205095
1988	244424
1989	277145
1990	277166
1991	266145
1992	290208
1993	337638
1994	368959
1995	394983
1996	353148
1997	376284
1998	393814
1999	402913
2000	486030
2001	422570
2002	360032
2003	350392
2004	370150
2005	371661
2006	376189
2007	397175
2008	378296
2009	319437
2010	327069
2011	362677
2012	368207
2013	373691
2014	395641
2015	400194
2016	425456
2017	481524